Both staff and customers can manage payment cards on a customer account.
The option is to Add and delete a card and set a card as default.
Adding a new card
Visit the customers profile
Navigate to the customers Wallet by choosing 'Wallet'
Under Payment Methods select 'Add new'
Add in the new card details and click 'Submit', note: The new card will be set as the new default payment method and used for all existing and future membership renewals and payments.
The customer now has 2 payment methods in their wallet. Either one can be set to be the default payment card.